Noiseless gun.



J. C. COULOMBE.

NOISELESS GUN.

APPLICATION FILED FEB. 23, 1909.

Patented May 25, 1915.

JOSEPH C. COULOMBE, 0F NORTHFIELD, VERMONT.

NOISELESS GUN.

Specification of Letters Patent.

Patented May 25, 1915.

Application filed February 29., 1909. Serial No. 479,671.

To all whom it may concern Be it known that I, Josnrn C. COULOMBE, acitizen of the United States, residing at Northfield, in the county ofWashington and State of Vermont, have invented a new and usefulNoiseless Gun, of which the fol-- lowing is a specification.

My invention relates to a noiseless gun embodying a mufiling device,which is adapted to prevent noise occurring from any form of explosion,where the expanding gases, of said explosion, are allowed to exhaust, tothe air, through more or less confined media, such as tubes or pipes ora gun barrel. The principle involved in mufiiing is also applicable tothe exhaust pipes of internal coinoustion or other engines, where theexhaust is discharged under considerable pressure.

The objects of the invention are, first, to mufile or reduce the reportor noise of an explosion or expansion of gases, without interfering orretarding the passage or" any projectile propelled, by any suchexplosion, through a passage such as a gun bore.

A further object is to silence or reduce the report or noise ofexpanding gases, without so retarding the movement of the expandingfluid or gases as to cause back pressures.

A further object, is to reduce the recoil ordinarily caused by theexplosion or expanding gases and projectile, thereby greatly increasingthe accuracy of shooting and, at the same time, reducing the cost ofmainte nance of heavy artillery, obviating the shocks and jars due torecoil.

A still further object is to dissipate or reduce the noise ofexplosions, where they ocour in quick succession, through a conductor,as in steam and internal combustion engines, without inducing a backpressure or'loss of power.

Referring to the drawings: Figure 1 is a vertical semi-sectional viewshowing the vention as applied to a gun. Fig. 2 is a sectional view onenlarged scale of the parts shown in Fig. 1. Fig. 3 is a semi-front viewoi the hollow frustum 7 illustrated in Fig. 2. l ig. 4: is a side viewof a hollow frustum l0 illustrated in Fig. 2. Fig. 5 is a semi-frontview of a frustum 10. Fig. 6 is an end view taken from the right of Fig.2 with the holding plug removed. Fig. Y is a semi-front view of combinedhollow frustum and tube 8 or 9 with attached tubes 15 or 16. Fig. 8 is aside view of a gun barrel illustrating how it may be reduced andperforated. Fig. 9 illustrates the principle of the invention applied tothe exhaust of an internal combustion or steam engine. Fig. 10 is an endviewof the frustums of Fig. 9 looking from the left of said figure andshowing the gradually decreasing exhaust outlets of the hollow frustums.

The invention is herein illustrated in various forms. lln one form it isshown, as applied to a gun barrel, for silencing the report or noiseordinarily caused by the discharge of the gun and when so applied,affords a continuous unbroken guide for the projectile, at the same timeaffording means for dissipating the nominal high pressure of the gaseswhich impel the projectile. The same form may be applied to anyform ofoutlet through which gases, under pressure, are moving preventing anynoise which it is desired to silence. in a second form illustrated inFig. 9, there is no continuous guide, although there is a free passagealong or through which the expanding gases may be projected. lVhethcathepressure reducing apparatus is arranged over the barrel or tube, or incontinuation thereof, is quite immaterial, provided its form is such asto reduce the momentary rush and force of the expanding gases.

in the accompanying drawings, referring to Fig. 1, the numeral 1,denotes-a wooden shield piece ordinarily employed underneath the barrelor a high-powered riiie,while 2, indicates a similar wood piece on theupper side of the barrel. 3, is the rear sight and ll, the front sight.

The numeral 4 denotes a comparatively thin tube arranged about the gunbarrel and projecting along or in continuation of the barrel to anyrequired distance. As shown herein, it runs the full length of thebarrel from the muzzle to the breech and, of course, if used as asilencer for engines or the like, would be extended the requireddistance over the exhaust pipe of the engine or other apparatus.

The gun is provided with the regularly formed bore indicated at 5, andas shown herein, the barrel is reduced from a point, as at 6,illustrating a means, of lightening the barrel, to secure the sameweight of gun with the silencing mechanism applied thereto. The barrel6, may be perforated at various points, the number and size of theperfoleft for the bullet, as it passes through the bore. The bullet orprojectile is illustrated at 25, about to emerge from the muzzle. Theouter surfaceof the barrel is threaded at the muzzle and a locking plug27, has a threaded opening cooperating therewith and adapted to hold theouter casing l, and appurtenant parts in place'and in fixed relation onewith another.

l Vithin the outer casing t, are arranged a series of hollow frustumswhich fit snugly over the barrel and have their bases extending to ortoward the inner surface of the outer casing 4. As illustrated, thefirst hollow frustum 7, fits snugly about the barrel 5, and extends tothe outer casing 4:. This serves to make a chamber between the barreland outer casing. The gases in expanding pass through the perforationsof the barrel, into this chamber, are directed against the frustum l,and are forced back along the chamber, between the barrel and outertube, expanding clear back to the breech or end of the chamber, thenback through the perforations into the barrel and out again into thenext succeeding chamber formed by the hollow frustum 8, and frustum 7.The hollow frustum 8, is preierably combined with a tube 15, whichextends toward the muzzle, and being smaller in diameter than the outertube, forms a chamber 13 intermediate the two tubes, llnto this chamberthe gases may expand after passing through the oerforations of thebarrel and between the hollow frustums 7 and 8. They may then return,through the same perforations, into the barrel and out again into thechamber formed between the frustums 8 and 9., This hollow frustum 9, isto the frustum 8, though smaller in diameter and, with its tube 16,forms a chamber 14:, between its tube and the tube 15. The gases passingbetween the frustums 8 and 9 may pass into the chamber, thus formed, andupon return may pass through the perforations into the barrel and outagain into the chamber formed by the hollow frustums 9 and 10. There ispreferably a series of chambers formed by similar frustums 10, which aretitted snugly between the barrel and the tube 16, and into thesechambers, the gases alternately expand and pass out again into the boreof the barrel and finally find their way out through the muzzle into theopen air. By this means, the initial high pressure of the gases isgradually, though completely broken up and dissipated and said gasesfinally pass off, in a prolonged exhaust, thus lessening the noise andcounteracting the recoil. lfiach of the frustums are provided withopenings at their tops, as at 17, 18 and 19, which lit snugly over theperforated barrel and should be located just in advance of the barrelperforation.

In Figs. 4 and 5, there is illustrated a convenient arrangement by whichthe several frustums 10, with their tubes, may be nested together, tosecure uniform adjustment and spacing.

An annular shoulder 2t, as indicated in F ig. l is formed at the largerend of the frustum 23, and over this may be slid the end of the tube 20,of the frustum illustrated in Fig. 5. Any desired number of the frustumsmay, in this way, be nested together, giving the exact and properspacing for their arrangement within the outer casing. As the frustumsare all of substantially the same form and size, the parts in Figs. 4and 5 illustrating two of these frustums with their tubes bear identicalreference characters.

In Fig, 9, the invention is illustrated as used in continuation of anexhaust tube such as the muffle er exhaust tube of an engine. Tn thiscase, in order to secure a greater silencing ellect w'thin a givenlength and area, the frustum 7, at the inlet side, has an opening 18, oflarger diameter than the succeeding hollow frustums of the series. Theexhaust pipe 6, which projects into the outer casing 4 has its endlocated adjacent to the hollow frustum 7, and the hole or opening,through the end or top of the frus tum '7, is of substantially the samediameter as that of the inside of the exhaust pipe. The gas pressure isgradually reduced as the gas passes successively from one to another ofthe chambers formed by the several hollow frustums. The diameters of theopen ings through these successive frustums may be gradually reduced.The projected gas is carried up into taese successive chambers where itexpands and finally exhausts through the last frustum opening and. theoutlet 27.

By having a continuous opening, from the exhaust pipe through the gaspressure reducing mechanism, which is unobstructed, except as to thedifi erent diameters of frustums, the projected column of gas underinitial high pressure, is gradually and effectively broken up, thusgiving a great reduction in noise without causing any appreciable backpressure.

Figs. 2 to 6 inclusive, as shown, are practic-ally of actual size. Thediameter of the outer tube need not exceed one and threechambers. It hasbeen my object, therefore,

to make the first chambers or compartments as large as possible and byplacing the frusturn 7, as indicated, the gases under the highesttension will be thrown into the long chamber illustrated as reachingback to the breech. The frustum 8, with its tube 15 forms another longchamber extending toward the muzzle, while the frustum 9 with its tube16 forms still another similar long chamber.

Obviously, any desired number of chambers may be used and the relativesize of the chambers, as well as their arrangement, will depend upon theforce of the explosion, the volume of the expanding gases and the sizeor caliber of the tube through which the gases are exhausted. Therefore,any such modifications of arrangement as to details is contemplatedwithin the scope and intent of the resent invention.

What I claim as m invention and desire to secure by Letters atent is 1.In a silencer for compressed gases freed from a conducting tube, aeasing into which the gases are discharged of relatively large crosssectional area as compared with the tube, and partitions arranged withinthe casing and dividing it into a plurality of chambers of successivelysmaller size from the first into which the tube discharges, andperforated in line with the axis of discharge from the tube, the saidchambers being closed to the open and to each other except through thesaid perforations in the partitions.

2. In a silencer for compressed gases freed from a conducting pipe ortube, a cylindrical casin into which the gases are discharged of reatively large cross area as compared with the said conducting pipe ortube and partitions within the casing having frustoconical heads andcylindrical extensions, the said cylindrical extensions being concentricand the partitions being closed except at the ends of the frusto-conicalsections, whereby there are formed within the casing successive chambersclosed except at the ends of the frusto-conical sections where onechamber communicates with the next.

3. The combination of a cylindrical casing, frustums having tubesattached to their bases, and the innermost of said tubes having frustumsattached therein at intervals.

4. The combination of a cylindrical casing, a perforated exhaust piperunning through said casing, and havin fitted therein, between saidcasing an said pipe, frustums having tubes attached to their bases andthe innermost tube having frustums fitted therein at intervals.

5. The combination of a cylindrical casin a partially and slantinglyperforated ex aust pipe running through said casing, being imperforatefor a distance at both extremities, and having fitted between saidcasing and said pipe or barrel, consecutively, a frustum, one or morefrustums having attached tubes, and frustums attached to the innermostof said tubes.

6. The combination of a gun barrel, a easing into which the gases fromthe gun barrel are discharged, and a partition dividing the casing intoclosed chambers, the first of which is of relatively large size andextends backward toward the breech of the gun and partly surrounding the11 barrel and the next chamber being 0 smaller size than the first andextendm forward from the partition and being su stantially concentricwith the axis of the bore of the gun barrel and communicating with thefirst chamber only through an opening in line with the bore of the gun.

In testimony whereof, I have signed my name to this specification in thepresence of two witnesses.

JOSEPH C. COULOMBE.

Witnesses:

E. A. CHASE, E. L. BEAN.

